The control of ectoparasites, such as fleas, ticks, biting flies and the like, has long been recognized as an important aspect of human and animal health regimes. Traditional treatments were topically applied, such as the famous dips for cattle, and indeed such treatments are still in wide use. The more modern thrust of research however has been towards compounds which can be administered orally or parenterally to the animals and which will control ectoparasitic populations by poisoning individual parasites when they ingest the blood of a treated animal.
The control of endoparasites, or intestinal parasites, has also been an important aspect of human and animal health regimes.
Although a number of ectoparasiticides and endoparasiticides are in use, these suffer from a variety of problems including a limited spectrum of activity, the need for repeated treatment and, in many instances, resistance by parasites. The development of novel endo- and ectoparasiticides is therefore essential to ensure safe and effective treatment of a wide range of parasites over a long period of time.
In addition, there are advantages to controlling both ecto- and endoparasites with one therapeutic agent. For example, a single parasiticidal agent is easier to administer and to incorporate into management regimes. Dosing may also be more accurately controlled. Interfering effects may be eliminated, and in certain circumstances synergistic combinations may be identified and exploited.
A need therefore exists for novel methods of controlling parasites by providing compositions effective for such control when administered orally, parenterally, or topically to a person or animal. The present invention addresses that need.